Actuating mechanism for automatic shotgun



March 23, 1965 P. c. BERETTA 3,174,401

ACTUATING MECHANISM FOR AUTOMATIC SHOTGUN Filed Dec. 20, 1961 5 Sheets-Sheet 1 March 23, 1965 P. c. BERETTA 3,174,401

ACTUATING MECHANISM FOR AUTOMATIC SHOTGUN Filed Dec. 20, 1961 5 Sheets-Sheet 2 INVENTOR. fife (hm: Jaw/'74 March 23, 1965 P. c. BERETTA 3,174,401

ACTUATING MECHANISM FOR AUTOMATIC SHOTGUN Filed Dec. 20, 1961 3 Sheets-Sheet I5 4 E 5' 22 i 'z z INVENTOR. fisyfirw 59m n:

United States Patent 3,174,401 AQTUATENG MEHAN1SM FER AUTQ- MATitC SHOTGUN Pier Carlo Beretta, Via Siepi 6, Gardens Vat Trompia, Brescia, ltaly Filed Dec. 20, M61, Ser. No. 169,349 (Iiaims priority, application Italy, Jan. 29, 1961, 642,736; June 10, E61, 10,720/61 4 (Ilaims. (til. 8--192) The principle on which gas-operated firearm actions Work is already known: gas coming from the barrel by way of a suitable passage provided for it, is made to act under pressure on operating devices of the firearm to discharge the empty cartridge and prepare it for refiring, thereby causing alternating firing ejection and reloading of the firearm in a continuous, automatic or semiautomatic cycle.

The term reloading mechanism as used hereafter, will be understood to include the mechanism to accomplish all the reloading steps including the ejection of the empty cartridge from the barrel, etc.

Using known systems, the gas is tapped from the barrel as soon as the projectile, in the course of its travel along the barrel, has passed beyond the point where the opening or passage made through the wall of the barrel is located, said position differing according to various models of firearms. The pressure of the gas is proportional to that of the gas generated by the explosion of the cartridge and, since the cartridges used in shot guns may come from different sources, said pressure is not constant, but varies as a function of the powder charge in the cartridge, consequently, the pressure of the gas tapped off from the barrel in the same firearm may take on appreciably different values such as to exert, at times, excessive or premature pressure on the operating mechanism of the firearm, with resulting premature opening of the breech block and trouble in ejecting the empty cartridge, causing jamming of the firearm.

This invention has overcome this disadvantage by means of a device so constructed that the gas shunted from the barrel, instead of acting directly on the aforementioned mechanisms, acts through a means provided with a flexible reaction, which receives the first impulse from the gas, stores it, and transmits it to the breech-lock mechanism, etc. of the gun with a delayed action, for the purpose of allowing the pressure inside the barrel to be reduced to a tolerable limit, which is substantially uniform and proportional to the reacting force of the flexible member with which the device is equipped.

The device embodying this invention thus comprises one or more flexible means which becomes charged with energy upon receiving the instantaneous impulse of said gas, accumulating an amount of energy which is practically constant and independent of the pressure of the explosion. This energy is restored during the phase when the flexible member is released, giving up its charge so as to drive those members comprising the breech lock, triggering mechanism, and the like.

One important advantage of this device consists in the fact that the gas which is shunted off from the barrel is not allowed to expand inside the gun after having charged the spring, but, instead, is quickly discharged into the surrounding air, avoiding the deposit of scale and impurities caused by the explosive, such as are always detrimental to the firearms operation.

The actuating device embodied in this invention also prevents excessive and detrimental strains from being placed on the firearms mechanism such as could unfavourably effect its operation or the life of its moving parts.

The accompanying drawings show two forms of em- 3,174,401 Patented Mar. 23, 1955 "ice bodiment of the invention, to be treated as illustrative of the invention and non-restrictive, wherein:

FIG. 1 is a side view of the shotgun to which the first 0f the two embodiments of the invention described herein has been applied.

FIG. 2 is a longitudinal cross sectional view taken along lines 59 in FIG. 5, to show all the parts which are present which could not otherwise be made visible.

FIG. 3 is a diagram representing the phase in which the devices which actuate the reloading mechanism and devices connected with said mechanism start their return stroke.

PEG. 4 represents the phase at or just following the ejection of the empty cartridge.

FIG. 5 is a transverse section along 5-5 in FIG. 2, but with the parts in their true position.

FIG. 6 is a side view of a shotgun to which the second form of embodiment of the invention has been applied.

FIGS. 7 and 8 are sections of the same firearm, taken in a longitudinal, vertical plane, with the parts in their normal positions, that is, at the start of the cycle of operation.

FIGS. 9 and 10 are also vertical sections with the moving parts at their end positions after the trust has been applied by the pressure of the gas tapped off from the barrel during the explosion of the cartridge; in this phase the empty cartridge is still in the barrel.

FIGS. 11 and 12 are the positions taken on by the moving parts at the end of their return stroke under the action of the loading spring when the pressure exerted by the gas has ceased; in this phase the breech is fully open.

FIGS. 13 and 14 are two cross sections of the firearm taken along planes 13-43 and 14-14 in FIG. 6.

Returning to FIG. 1, the firearm is seen from the side on which the cocking rod 5 is located; it should be pointed out, though, that the complementary devices are not arranged symmetrically in relation to the barrel, but instead, that the cocking rod 5 and the gas outlet nozzle 8 are located at sides opposite one another as shown in FIG. 5.

The gun comprises the barrel 1, the tubular magazine 2 which holds the cartridges, the loading spring 3 fitted over magazine 2 and working against the slide 4 which receives the impulse of the gas tapped off from the barrel: the cocking rod 5 is connected with the reloading mechanism of known type, the description of which is therefore omitted, said mechanism being housed in the breech end of the firearm and being operated by the secondary impulse developed by the reaction of loading spring 3 is transmitted; the front end of rod 5 is equipped with protruding wings 6, pivoting like a scissors radially with respect to the axis of rod 5 under the action of a counteracting spring located between said wings.

FIG. 2 shows a hole 7 made in the wall of the barrel to tap off gas released by the explosion, said gas being guided to pass through a cylindrical nozzle 8 integral with the barrel, the flow of gas being directed towards the muzzle of the barrel; a small cylinder 9 which is closed at the bottom and is integral with sliding sleeves 4, fits over said nozzle 8, sleeve 4- being on the outside of tubular magazine 2 and carrying, on its opposite side a sec- 0nd part comprising a perforated lock ring 11 through which cocking rod 5 passes. The gas tapped 0 5 through hole 7 is thrown from nozzle 8 against the bottom of cylinder 9, pushing it forwards; cylinder 9 draws sliding sleeve 4- along with it and said sleeve 4 during its forward travel, compresses loading spring 3 up against the front end of tubular magazine 2, which is solidly fixed in place. A shock absorber it is connected with said front end of magazine 2 and positioned in such a manner as to receive and dissipate any extra force remaining in cylinder 9.

FIG. 3 shows the phase which follows the beginning of the return stroke and, consequently, the beginning reloading operation and the shift in position of the members associated with the reloading mechanism. The gas remaining and flowing out of nozzle 8 is now discharged to the surrounding air, while the pressure in the barrel is reduced to very low pressure as a result of the projectile having already moved towards the muzzle.

The spring 3 expands again, pushing sliding sleeve 4 towards the breech end of the firearm and the sleeves perforated appendage 11 strikes against wings 6, protruding from the cocking rod 5, pushing said rod backwards; said rod actuates the reloading mechanism with which it is connected, causing it to open and, at the same time, the recovery spring of the cocking rod-breech mechanism group, starts its depression being situated as is normally the case, towards the breech end of the firearm.

FIG. 4 shows phase at or just following the ejection of the empty cartridge: spring 3 has opened up all the way, pushing the sliding sleeve 4 along; the cocking rod 5 has completed the full length of its backward travel, pushed by the two expanding wings 6 engaged by ring 11 integral with sleeve 4.

The breach has thus been opened all the way, ejecting the empty cartridge and a new cartridge is ready to pass from the tubular magazine into the firing chamber.

At this point the expanding wings 6, protruding from the end of the cocking rod 5 are automatically retracted due to the effect of the compressing action exerted against them by perforated ring 12, integral with the rear portion of tubular magazine 2.

The formerly protruding rings having been retracted, the cocking rod 5 is ready to start its travel in the opposite direction; the end of rod 5 with its wings folded in, passes through perforated ring 11, integral with sliding sleeve 4 and rod 5, moving forwards under the thrust exerted on it by recovery spring (FIG. 2) of the cocking rod mechanism as said spring expands, takes up the position shown in FIG. 2. At the same time, recovery spring 15 reloads the firearm so that it is ready to start upon a new cycle.

The variant embodying the invention which is shown in FIGS. 6 through 14 also comprises a barrel, the tubular magazine 2 for the cartridges or shells, the spring 3 counteracting the sliding of sleeve 4 and, in this form of embodiment sleeve 4 is provided with a ring 4' which receives the thrust exerted by the gas shunted off from the barrel; cocking rod 5 serves to connect sliding sleeve 4; with the reloading mechanisms, etc., housed in the breech,

to which it transmits the secondary impulse developed by I the reaction of spring 3; 7 is the hole or passage made in the wall of the barrel to tap oil the gas from the explosion, said gas being guided in a cylinder 9 integral with the barrel and alongside it; inside said cylinder 9 a piston S is free to slide, being equipped with a rod issuing from the head of cylinder 9 and going in the direction of the muzzle, In the normal position (FIG. 7) the front end of said rod comes to rest against ring 4 incorporated in sliding sleeve 4.

The cocking rod 5 is integral with sleeve 4 at one end and its other end slides inside such breech housing 13 and along piston member 20. The breech housing 13 contains the means to eject the empty cartridge and reload the firing chamber (not shown). Within piston member 20, a rocking tab 2-1 is pivotally mounted so that it can project outwardly from said member 29, being urged outwardly by a spring pressed button 22. In the normal position of the firing mechanism with the cartridge in place ready to be fired, the tab 21 is held at the level of the body of the piston 2% by the inside face of the cocking rod 5 as shown in FIG. 8. When rod 5 moves forward, tab 21 moves outwardly from piston under the force of button 22 to the position shown in FIG. 10.

The operation of the second form of embodiment mp resented in FIGS. 6 through 14 will be apparent from FIGS. 6 and 7 which shows the device at the starting phase of its cycle of operation which progresses as follows:

Having fired the cartridge, the gas shunted off from the barrel 1 through hole or passage 7 penetrates as far as the end of cylinder 9 in a suitably provided chamber and acts directly on the bottom of piston 8 which is thrust forwards; the forward extension of piston 8 then issues from the front end of cylinder 9, striking against ring 4', integral with sliding sleeve 4, which, due to the effect of this impulse is drawn along forwards and, during its travel, compresses spring 3 bringing it up tight against the fixed front end of the tubular magazine. Simultaneously the cocking rod 5 integral with sleeve 4, is also drawn forward, allowing tab 21 to protrude from the piston body 26.

A flexible shock absorber is connected with the head end of the tubular magazine 2 to receive and, if necessary, to dampen any live force remaining in the sleeve 4 and in its ring 4.

FIG. 9 is a successive phase of the cycle, that is, the beginning of the return motion of the sliding sleeve, with the consequent starting of the reloading operation.

The shunted gas, flowing from passage 7 drops off in pressure inside the barrel following the translation of the projectile towards the muzzle of the barrel and, as a result the pressure is also reduced inside cylinder 9.

Simultaneously spring 3 expands and pushes sliding sleeve 4 and cocking rod 5 to which the latter is connected, back towards the breech end; said rod 5, during its backwards motion, engages tab 21, now protruding from the body of the piston 29 due to the effect of the springpressed button 22. Thus the rod 5 engages the piston 20, pushing it towards the breech end of the firearm, also starting to compress the recovery spring, which actuates the reloading mechanism, etc., said spring being located, conventionally, in the rear portion of the firearm.

FIG. 11 shows the position of the sleeve and rod 5 at the moment or just after the empty cartridge has been ejected; spring 3 has completely expanded, pushing sliding sleeve 4 back to its original position and cocking rod 5 has completed its backward course, pushing the tab 21 and, with it, the piston 20, which has thus opened the breech all the way, allowing the empty cartridge to be ejected while a new shell is ready to move from the tubular magazine into the firing chamber by the usual means.

In the phase of the backward movement of the piston 29 when it has reached its extreme position (FIG. 12) tab 21 is engaged by nib 24, integral with breech housing 13, said nib 24 having its inside face sloping to form an inclined plane; the nib 24 gradually engages the lower or outside face of tab 21, obliging the latter to retract inside the body of the piston 20 until it comes flush with its surface. This having taken place, there is no longer any linkage or point of engagement between the cooking rod 5 and the piston 20 and the latter now starts its travel in the opposite direction to take up its closed position; being pushed to this position by the recovery spring. Cooking rod 5 and sliding sleeve 4, instead, remain in the position which they have already reached and we thus have a re turn to the situation shown in FIGS. 7 and 8, allowing the cycle to repeat.

What I claim is:

1. In an automatic firearm of the shotgun type adapted to fire cartridges with varying proportions of powder charges and comprising a barrel, a magazine for cartridges extending parallel to said barrel and means to eject empty cartridges and reload the firing chamber from said magazine, an improved actuating mechanism for said means to eject empty cartridges and reload the firing chamber comprising coil spring means surrounding the cartridge magazine,

means on said magazine adjacent the muzzle end of the firearm to retain one end of said coil spring means,

sleeve means surrounding said magazine adjacent that end of the coil spring means nearest the breech end of said firearm and adapted to move towards the muzzle end of the firearm to compress said spring means, said sleeve means having a return stroke im-- parted thereto by said compressed spring means,

a cylinder-piston actuating means,

one part of the cylinder-piston means being movable to impel said sleeve means against the action of said coil spring means,

the other part of the cylinder-piston means being fixed to the barrel of said firearm,

the movable part of said cylinder piston means being shorter than the length of movement of the sleeve means as determined by the coil spring means whereby the positive impelling force applied from the cylinder-piston means is limited to a portion of the length of movement of said sleeve means,

nozzle means connecting the barrel to the interior of the cylinder of said cylinder-piston means whereby gas from a discharged cartridge Will force the moveable part of the cylinder-piston means to move to ward the muzzle of said firearm,

said actuating mechanism for the means to eject empty cartridges and reload the firing chamber including an actuating rod movable toward and away from the breech end of said firearm,

said actuating rod comprising catch means in a fixed position thereon operable to connect said rod to said sleeve means only on the return stroke of the sleeve means whereby the force applied to said actuating rod is always the same regardless of the initial pressure applied to said cylinder piston means.

2. The automatic firearm as claimed in claim 1 wherein the cylinder of said cylinder-piston means is attached to the sleeve means and the piston is fixed to the barrel.

3. The automatic firearm as claimed in claim 1 whereon the piston of said cylinder-piston means contacts the sleeve means and the cylinder is fixed to the barrel.

4. The automatic firearm as claimed in claim 1 wherein the peripheries of the barrel and the magazine are in contact With each other, said nozzle means being positioned parallel to and intermediate the barrel and magazine on one side of the contacting region, said actuating rod being positioned parallel to and intermediate the barrel and magazine on the opposite side of the contacting region thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,749,137 3/30 Hudson 89--192 X 2,331,347 10/43 Rehnberg 89192 2,386,205 10/45 Garand 89-191 X FOREIGN PATENTS 54,506 3/38 Denmark. 147,371 7/20 Great Britain.

BENJAMIN A. BORCHELT, Primary Examiner. 

1. IN A AUTOMATIC FIREARM OF THE SHOTGUN TYPE ADAPTED TO FIRE CARTRIDGES WITH VARYING PROPORTIONS OF POWDER CHARGES AND COMPRISING A BARREL, A MAGAZINE FOR CARTRIDGES EXTENDING PARALLEL TO SAID BARREL AND MEANS TO EJECT EMPTY CARTRIDGES AND RELOAD THE FIRING CHAMBER FROM SAID MAGAZINE, AN IMPROVED ACTUATING MECHANISM FOR SAID MEANS TO EJECT EMPTY CARTRIDGES AND RELOAD THE FIRING CHAMBER COMPRISING COIL SPRING MEANS SURROUNDING THE CARTRIDGE MAGAZINE, MEANS ON SAID MAGAZINE ADJACENT THE MUZZLE END OF THE FIREARM TO RETAIN ONE END OF SAID COIL SPRING MEANS. SLEEVE MEANS SURROUNDING SAID MAGAZINE ADJACENT THAT END OF THE COIL SPRING MEANS NEAREST THE BREECH END OF SAID FIREARM AND ADAPTED TO MOVE TOWARDS THE MUZZLE END OF THE FIREARM TO COMPRESS SAID SPRING MEANS, SAID SLEEVE MEANS HAVING A RETURN STROKE IMPARTED THERETO BY SAID COMPRESSED SPRING MEANS, A CYLINDER-PISTON ACTUATING MEANS, ONE PART OF THE CYLIDER-PISTON MEANS BEING MOVABLE TO IMPEL SAID SLEEVE MEANS AGAINST THE ACTION OF SAID COIL SPRING MEANS, THE OTHER PART OF THE CYLINDER-PISTON MEANS BEING MOVABLE TO THE BARREL OF THE FIREARM, THE MOVABLE PART OF SAID CYLINDER PISTON MEANS BEING SHORTER THAN THE LENGTH OF MOVEMENT OF THE SLEEVE MEANS AS DETERMINED BY THE COIL SPRING MEANS WHEREBY THE POSITIVE IMPELLING FORCE APPLIED FROM THE CYLINDER-PISTON MEANS IS LIMITED TO A PORTION OF THE LENGTH OF MOVEMENT OF SAID SLEEVE MEANS, NOZZLE MEANS CONNECTING THE BARREL TO THE INTERIOR OF THE CYLINDER OF SAID CYLINDER-PISTON MEANS WHEREBY GAS FROM A DISCHARGED CARTRIDGE WILL FORCE THE MOVEABLE PART OF THE CYLINDER-PISTON MEANS TO MOVE TOWARD THE MUZZLE OF SAID FIREARM, SAID ACTUATING MECHANSIM FOR THE MEANS TO EJECT EMPTY CARTRIDGES AND RELOAD THE FIRING CHAMBER INCLUDING AN ACTUATING ROD MOVABLE TOWARD AND AWAY FROM THE BREECH END OF SAID FIREARM, SAID ACTUATING ROD COMPRISING CATCH MEANS IN A FIXED POSITION THEREON OPERABLE TO CONNECT SAID ROD TO SAID SLEEVE MEANS ONLY ON THE RETURN STROKE OF THE SLEEVE MEANS WHEREBY THE FORCE APPLIED TO SAID ACTUATING ROD IS ALWAYS THE SAME REGARDLESS TO THE INITIAL PRESSURE APPLIED TO SAID CYLINDER PISTON MEANS. 